Southern Bluefin Tuna

Threatened Status:

Location:

Atlantic, Pacific and Southern Oceans. In Australia, 95% are caught in the Great Australian Bight.

If ever there was a fish that best represented all that is wrong with the way we fish, the Southern Bluefin Tuna would win the dubious award.

Southern bluefin tuna are ‘critically endangered’ and population levels are down to 5% of original, pre-fishing levels, yet rampant fishing of this species continues.

Facts About Southern Bluefin Tuna

Southern bluefin tuna can grow to 225 cm in length and weigh up to 200kg in weight – making them ocean giants

They have one of the longest migrations of any creature on the planet – spawning only in the Indian Ocean near Java and navigating the southern hemisphere’s seas before reaching Australian shores

During their migration, Southern bluefin tuna spend up to 84% of their time in the Australian Fishing Zone

Southern bluefin tuna are classified as ‘critically endangered’ on the IUCN’s Red List of threatened species, which means it ‘faces an extremely high risk of extinction in the wild’

Threats to Southern Bluefin Tuna

Southern bluefin tuna is the most popular variety of tuna out of all the species available on the market. It is in high demand for sashimi, particularly in Japan (1). Bluefin tunas sell for up to hundreds of thousands of dollars for an individual fish, and the Australian southern bluefin tuna industry worth over $100 million annually (2). With all of this in account, the pressure is on for this critically endangered fish.

As the fish migrate vast distances, they swim into areas that are managed by a number of different countries, of which Australia is one. As such, southern bluefin tuna are managed by a collaboration of nations. As a result of their migration route, different countries pick off the fish as they come within reach of a coastline. The Commission for the Conservation of Southern Bluefin Tuna (CCSBT) allocates what each nation can take from the stock, and Australia currently has access to around 4,200 tonnes of fish per year (3).

More than 95% of Southern bluefin tuna are caught as juveniles in the Great Australian Bight before being fattened up in sea cages and exported to Japan. Targeting large numbers of juvenile, pre-spawning fish means it is extremely difficult to rebuild future stock.

Recreational fishers also target southern bluefin tuna. In 2012, the Victorian Government published the first estimate of recreational take. They found that during a five-month period in 2011, around 19,700 fish were caught and retained, which is about 240 tonnes of fish(3). Technically, this catch should be included in the total amount of fish the whole of Australia is allowed to extract by CCSBT. However, it remains to be seen how Australia will justify catching over its allocation.